TSC1 p.Leu355Met

Variant names:

• chr9-132911419-G-T
• rs587778002
• ENST00000403810.6:c.1063C>A
• TSC1 p.Leu355Met

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The ENST00000403810.6(TSC1):​c.1063C>A​(p.Leu355Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 14/17 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L355V) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 31)
• Consequence: TSC1 ENST00000403810.6 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.105
• Publications: 0 publications found

Genes affected

TSC1 (HGNC:12362): (TSC complex subunit 1) This gene is a tumor suppressor gene that encodes the growth inhibitory protein hamartin. The encoded protein interacts with and stabilizes the GTPase activating protein tuberin. This hamartin-tuberin complex negatively regulates mammalian target of rapamycin complex 1 (mTORC1) signaling which is a major regulator of anabolic cell growth. This protein also functions as a co-chaperone for Hsp90 that inhibits its ATPase activity. This protein functions as a facilitator of Hsp90-mediated folding of kinase and non-kinase clients, including TSC2 and thereby preventing their ubiquitination and proteasomal degradation. Mutations in this gene have been associated with tuberous sclerosis and lymphangioleiomyomatosis. [provided by RefSeq, May 2022]

TSC1 Gene-Disease associations (from GenCC):

• tuberous sclerosis

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• tuberous sclerosis 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P, Genomics England PanelApp
• lung lymphangioleiomyomatosis

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• tuberous sclerosis complex

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.22996268).

Variant Effect in Transcripts

ACMG analysis was done for transcript: ENST00000403810.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TSC1	NM_000368.5	MANE Select	c.1029+34C>A		intron	N/A	NP_000359.1	Q92574-1
	TSC1	NM_001406629.1		c.-31C>A		5_prime_UTR_premature_start_codon_gain	Exon 9 of 22	NP_001393558.1
	TSC1	NM_001406630.1		c.-31C>A		5_prime_UTR_premature_start_codon_gain	Exon 10 of 23	NP_001393559.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TSC1	ENST00000403810.6	TSL:1	c.1063C>A	p.Leu355Met	missense	Exon 10 of 10	ENSP00000386093.1	Q86WV8
	TSC1	ENST00000298552.9	TSL:1 MANE Select	c.1029+34C>A		intron	N/A	ENSP00000298552.3	Q92574-1
	TSC1	ENST00000490179.4	TSL:3	c.1029+34C>A		intron	N/A	ENSP00000495533.2	Q92574-1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 22

GnomAD4 genome Cov.: 31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Benign	-0.057	T
BayesDel_noAF	Benign	-0.32
CADD	Benign	13
DANN	Benign	0.88
DEOGEN2	Benign	0.22	T
Eigen	Benign	-0.75
Eigen_PC	Benign	-0.74
FATHMM_MKL	Benign	0.16	N
LIST_S2	Benign	0.18	T
M_CAP	Uncertain	0.12	D
MetaRNN	Benign	0.23	T
MetaSVM	Benign	-0.48	T
PhyloP100		-0.10
PROVEAN	Benign	0.11	N
REVEL	Benign	0.17
Sift	Benign	0.087	T
Sift4G	Uncertain	0.050	T
Mutation Taster		=100/0	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs587778002;

hg19: chr9-135786806;